The present invention relates to a method for producing a woven on a loom comprising a stop bar, at least one shed and a heddle (heald) particularly for use thereby.
On modern narrow fabric needle looms tapes are produced preferably with a crossed tie of warp and weft in known weaves (1High-1Low, 2H-2L, 1H-3L, 3H-1L, 2H-4L, 4H-2L, 4H-4L, 2H-6L, 6F-2L etc.). Controlling the threads in this way is achieved by inserting the threads into the heddle eyelets (mails), lined up on shafts having these special motions. To figure or letter such tapes as produced with a normal weave, warp threads for producing the product are inserted fully or partly in heddle eyelets knotted to coarse threads connected to lifters of a Jacquard loom.
By the associated possibility of controlling the long repeats individually programmed, the regular weave repeats, contrary to the above, coming from the shaft control can be flexible interrupted so that figures, emblems or contours are produced functionally or in the visual appearance by the contrasts between warp and weft material with weave interrupts or floating extensions. As a rule, woven tapes are produced in this way on modern narrow woven needle looms double-picked weft for weft. To render wovens elastic, additional elastic threads (bare or wrapped) can be worked in which, for example, in a 1H-1L weave result in even and uneven wefts becoming facing and backing wefts respectively. This is because the weft threads come to rest below and above in up and down motion of the elastic thread respectively.
For more rational production of such tapes it is known to double tape output by simultaneously picking the facing and backing weft thread (for example by means of a double needle technique). This is achieved by forming a double shed by separating the upper thread position from the lower thread position in the middle mainly by elastic warp threads. Rationalizing tape production in this way in combination with jacquarding necessitates Jacquard looms capable of producing three-point shedding per heddle by making use of two control elements. However, the programming needed for this is correspondingly complicated.
On modern wide looms individual warp thread control is applied, likewise with the aid of Jacquard looms, to produce wovens with figures, emblems or contours. For this purpose the weft threads are picked to also permit the formation of two-ply wovens, where necessary, by, for example, the uneven picks forming more the backing layer and the even picks forming more the facing layer, or vice-versa. Interrupting the thread motion, producing the two-ply woven, by a thread motion which produces a link between facing and backing woven permits contouring as desired. Existing methods and devices employed therefor are no longer sufficiently suitable to produce the required woven quantity per unit of time or are too complicated and expensive. Apart from this, the Jacquard looms employed in known methods are subjected to extremely high loading and wear out correspondingly prematurely.
The invention is based on the objective of proposing a method for producing a woven and a heddle (heald) particularly for use thereby whilst avoiding, or at least greatly reducing, the disadvantages known with prior art. This objective is achieved by a method as it reads from claim 1 and by a heddle (heald) as it reads from claim 4. The advantages of the method in accordance with the invention and of the heddle as employed thereby can be described as follows. This method now makes it possible to double output by employing to advantage a double pick technique (picking two superposed wefts simultaneously) in creating with normal halved basic weave placement (1H-1L from 2H-2L and 2H-2L from 4H-4L, etc) high/low shedding shaft-controlled by (for example as with elastic tapes) middle positioning the (elastic) threads located in the middle shed by interrupting the motion of normal keying threads as needed for figuring the woven by halting the motion despite the full shaft stroke. Halting the motion is attained by one end of the slotted heddle controlled up/down by a corresponding normal Jacquard heddle motion, the warp thread guided in the slotted heddle being unable to move beyond the middle position.
In the method in accordance with the invention the warp threads having the function of producing a figure, emblem and/or contour are inserted not only into ordinary heddles but in addition also into heddles in accordance with the invention having a slotted eyelet (elongated mail). At the locations at which no figure point is needed the corresponding slotted heddle is positioned for example down [up] in which the slot is no obstruction to the threads which are moved up/down by a normal shaft motion with ordinary heddles, because of the slot position. Controlling the slotted heddle up [down] by a normal control pulse and tying in the slotted heddle so that the lower [upper] end of the slot is located in the middle or middle shed position halts the greater warp thread motion—produced by the ordinary heddles—in the middle or middle shed position and prevents it from implementing a normal weave pattern in thus making it possible to produce in each case a figure point (for example, a warp or weft portion visible outside a woven ply) in the normally programmable long repeat. The big advantage afforded by this is that although the programming is normally done on machines which implement only up/down control, double-shedding is now achievable by this approach in thus producing the woven twice as fast than in existing prior art methods. It is to be noted that the square bracketed [ ] positions above are intended to replace the positions directly indicated before when a heddle working in the opposite direction is meant.
Further huge advantages materialize when using the method in accordance with the invention and the heddle as employed therein on wide looms. In this arrangement, when using machines for example featuring double, simultaneous picking, e.g. double grip looms, through weaves can be alternated with hollow weaves by the threads weaving for example 1H-1L from the shaft motion being prevented from implementing their full motion individually with correct tie-in with (upper or lower) end of the slot in the middle shed when additionally drawn in the slotted heddle on Jacquard loom control. Alternating up/down or vice-versa down/up of each individual slotted heddle as controllable individually by the Jacquard loom over the full width of the woven in halting the full motion of the warp thread in accordance with the shaft motion in the middle shed enables figures or functional contours to be produced. Applying the method in accordance with the invention and the slotted heddle in accordance with the invention doubles output for the same loom speed and with a corresponding desired woven structure coupled with the advantage of an enormous reduction in the motion intensity of the Jacquard loom adding to its life.